In the current color photographic process, the most commonly practiced system is the so-called negative-positive system wherein a subject is photographed with a color negative film, and the enlarged image is printed onto a color paper to produce a color print. One outstanding reason for such popularity of this system is that color negative films have a very wide range of latitude of exposure levels, and this very seldom results in failure in image-taking during photographing with a camera; this means an ordinary one who is a layman lacking in expertise in photography can readily enjoy color photography. This advantage is an outstanding feature of the negative-positive system, and is not readily available with a reversal film or the like; it is important that a color negative film have a wide range of an exposure latitude.
The color negative films for photographing with a camera, and that are commercially available, contains, in combination, in order to achieve a wide range of an exposure latitude, in each of the negative film, each of the blue-, green- and red-sensitive layers independently takes a multilayer constitution comprising both a high-sensitivity emulsion layer containing larger size silver halide grains and a low-sensitivity emulsion layer containing smaller size silver halide grains.
However, a silver halide photographic light-sensitive material containing different groups of silver halide grains, where the groups have grains sizes significantly different with each other, incurs various problems.
First, such a material is less stable to the variation of processing condition.
In contrast to color reversal films, the color negative films are developed in various photofinishing laboratories, more possibly in various processing conditions. Therefore, the higher processing stability relative to change in processing conditions is required of the color negative films.
Second, standing stability of coating emulsions of such a type of film is inferior.
Third, due to differences in influence of an inhibitor diffused from another layer, it is difficult to endow each color with gradation of good tone reproduction.
There is another technique available for improving a stability with respect to variation of processing condition, wherein emulsions independently contains silver halide grains comprising substantially identical average size subjected to chemical sensitization, whereby to each of the divided emulsions is added a sensitizing dye in a varying molar ratio, and then the separated emulsions are blended together (Japanese Patent Publication Open to Public Inspection - hereinafter referred to as Japanese Patent O.P.I. Publication - No. 244944/1985, and the like). This re-united type emulsion, however, in the course of a standing period preceding a coating operation, undesirably develops adsorption equilibration of dye among grains.